Circuit interrupter



Sept. 26, 1944. H.L. RAWLINS 2,359,153 CIRCUIT INTERRUPTER Filed May 3,1941 3 Sheets-Sheet 2 WITNESSES:

INVENTOR gjbazmm Sept. 26, 1944. H. L. RAWLINS 2,359,153

CIRCUIT INTERRUPTER Filed May 3, 1941 3 Sheets-Sheet 3 WITNESSES:INVENTOR Patented Sept. 26,

2,359,153 7 cmcurr mrnnaurrsa Herbert L. Rawlins, Wllkinsburg, Pa.,assignor to Westinghouse Electric & Manufacturing Company, East-Pittsburgh, Pa.,

vania.

Pennsyl a corporation of Application May 3, 1941, Serial No. 391,644 33Claims. (Cl. 200114) This invention relates, in general, to electriccircuit interrupters, and more specifically, to drop-cut fuse cutouts.

One object of this invention is to provide a novel type of drop-out fusewhich is of relatively simple construction and capable of ready and easyassembly and is eflicient in operation.

Another object of this invention is to provide a novel drop-out fuseconstruction especially adapted for use with an enclosed fuse structure.

Another object of this invention is to provide a fuse of the typedescribed which is especially adapted for ready attachment or detachmentwith respect to supporting means and which may be attached or detachedby means of a hook stick.

Another object is to provide a novel assembly of a fuse and housingdoor.

Another object of this invention is to provide novel means for securinga fuse link to a fuse terminal.

These and other objects of this invention will become more apparent uponconsideration of the following detailed description of a preferred embodiment thereof, taken in connection with the accompanying drawings, inwhich:

Figure l is a longitudinal sectional view through an enclosedfusecoutout embodying this invention, with the fuse shown in the closedcircuit position;

Fig. 2 is a view like that of Fig. 1 but showing the fuse in an initialstage of its automatic dropout movement;

Fig. 3 is a partial sectional view of the lower end of a fuse like thatshown in Figs. 1 and 2, and certain parts being broken away. toillustrate an attachment for preventing movement of the fuse when itblows;

Fig. 4 is a partial front view of the fuse shown in Figs. 1 and 2, withthe fuse in an open dependingposition with respect to its housing;

, Fig. 5 is a bottom view of the fuse and door assembly shown in Figs.1, 2 and 4;

Fi 6 is a transverse sectional view taken substantially on the lineVI-VI of Fig. 1;

Fig.'-'l is an enlargedelevational view partially in section, of thefuse link securing means shown in Figs. 1 to 6; and

v Fig. 8 is a sectional view of the fuse securing means lookingsubstantially in the direction of the arrows VIII-VIII of Fig. 7.

In the embodiment of the invention illustrated in the drawings, the fuseis preferably provided with an insulating housing, 2 which may be of anydesired insulating material, preferably diepressed porcelain. Thehousing 2 comprises a rear wall 4, a top wall 6 and opposite side wallsThe rear wall 4 is provided with an .inwardly extending protuberance I 0forming with the in tegral flange II a transverse bafiie intermediatethe ends of insulating casing 2. The protuberance l0, as shown, isprovided with a cavity opening to the outer side of wall 4 adapted toreceive one end of a mounting supporting the casing, for example, from acrossarm hanger H adapted to be secured to the bracket 12 by bolt l6.Supporting bracket I 2 is preferably secured in the cavity ofprotuberance I0 by cementing material It which may be any well knowntype of cementingmaterial, or may be a metal cast in the cavity aroundbracket arm l2.

Within casing 2 there is provided upper and lower contact assemblies l8and 20, respectively, secured in cavities in the inner surface of rearwall 4 of the casing. The upper contactassembly it includes a forwardlyprojecting contact strip 2| of any desired conducting material, such forexample, as copper or the like, with a resilient backing strip 22overlying conducting strip 2!. The outer end of conducting strip 2| ispreferably bifurcated, and the outer end of resilient backing strip 22is preferably formed with three spaced tine portions, the outer ones ofwhich overlie the furcations of contact strip 2!, and

the middle one of which is formed with a downwardly projecting endportion 24 adapted to project downwardly between the furcations ofcontact strip 2|, to form a latch means for engagement with the upperend of a fuse, Similarly, the lower contact assembly 20 includes acontact strip 26 and resilient backing strip 28 overlying contact strip26, and the outer ends of these strips are preferably provided with anarcuate cutout portion for receiving the fuse when in operative positionwithin casing 2.

The contact and backing strips of both the contact assemblies I8 and 20are mounted in positionin casing 2 by a substantially U-shaped clampmember 30 having an enlarged bight portiOn for the reception of a lineconductor, with a screw 32 threaded through an aperture in one wall ofthe bight portion to clamp the conductor therein. The contact andbacking strips are received between the outer ends of U-shaped clamp 30,as is one leg of an angled supporting bracket 34. Securing means, suchfor example, as screws 36, are adapted to extend through the legs ofU-shaped clamp 30 and through apertures in the contact and backingstrips, and each angled supporting bracket 34 is provided with bracketl2 for slots in the outer edge thereof for receiving intermediateportions of screws 38 so that the entire contact assemblies may beslipped on or off brackets 34 when screws 38 are loosened, and

may be secured to the brackets merely by tightening screws 35 when theassemblies are in position. The other legs of angled brackets 34 aresecured in depressions formed in the inner surface of rear casing wall4, preferably in the same manner that supporting bracket I2 is securedin the cavity of protuberance l8.

The above-described structure has not been described in great detailbecause this structure is more particularly disclosed and claimed in thecopending application of H. L. Rawlins and E. H. Fischer, Serial No.379,076, filed February 15, 1941, entitled Electrical apparatus, andassigned to the same assignee as this invention. Accord-- lingly, for amore complete description of the details of insulating casing 2 andcontact assemblies,l8 and 2ll, and their association with casing 2,reference is hereby made to the aforesaid copending application.

-The open front of casing 2 is adapted to be closed by a door 38 ofinsulating material, such for example, as porcelain, a synthetic resinor the like. Door 38 comprises a door panel 48 having at the outersurface thereof an integral projection 42, extending outwardly andapertured as at 44, for the reception of a hook stick operating member,or the like, for manipulation of the door to open and closed positionswith respect tq casing. 2. The inner surface of door panel 48 isprovided intermediate the ends thereof with spaced, longitudinallyextending integral flanges 45, adjacent the upper ends of which, asviewed in Figs.- 1 and 2, there is provided an integral projection 48apertured-for the reception of a fuse 58.

The fuse 58 may be of a conventional form which "includes a fuse tube 52of any desired insulating material, such as fiber or a synthetic resin.The upper end of the fuse tube has secured thereto in any desiredmanner, such for example, as by threaded engagement, an upper metalterminal ferrule 54 provided with a terminal cap 58 threadedly engagedwith the outer end of the ferrule, for securing the head contact '53 ofa fuse link in conductive relation with respect to ferrule 54 and cap55. The lower end of fuse tube 52 is left open so that the tail 5| ofthe fuse linlq may extend out of the lower end of the fuse tube to befastened to a lower terminal. The fuse link also may be of anyconventional structure, and that illustrated includes a terminal head 53and tail 5| connected by a fusible means contained'within an insulatingtube 55 adjacent the upper end of fuse tube 52. This specific fuse linkstructure is more particularly disclosed and claimed in the copendingapplication of James M. Wallace, Serial No. 294,- 073, filed September9, 1939, on Circuit interrupters now Patent No. 2,343,723, issued March7, 1944, and assigned to the same assignee as the 8 present application.

As shown in the drawings, fuse 50 is assembled with door 38 by threadingfuse tube 52 downwardly through theaperture in projection 48, untilterminal ferrule 54 is seated on the upper side of projection 48.flanges 51 are providedconnected with door panel 48- and'projection 48,and are joined by a curved wall portion to conform to the curvature 'offuse terminal ferrule 54. Also, one of the flanges 51 is provided with athreaded apervture for receiving a set screw 58 to prevent removal ofthe fuse from projection 48, and set screw 48 is preferably adapted tobe received in a side aperture in terminal ferrule 54.

Door panel 48 is also provided at the inner side thereof with a secondintegral projection 80 adjacent the lower end thereof, which isapertured for reception of the lower end of fuse tube V 52. That is,when fuse tube 52 is threaded through aperture in projection 48 untilferrule 54 engages the upper side of projection 48, the lower end of thefuse tube will then be received in the aperture provided in lowerprojection 58. Extending upwardly from lower projection 58 and integraltherewith and with door panel 48, are spaced flanges 82 similar to upperflange 51,

and like these flanges, are joined by a curvedv connecting wall portionadapted to conform with the curvature of fuse tube 52. Flanges 82 areprovided below flanges 46 and are spaced slightly inwardly of flanges48, for a purpose which will hereinafter become apparent.

A supporting lower terminal assembly is adapted to be readily removablyassociated with the door and fuse assembly, and thisis accomplished bythe provision of a transverse slot or groove 64 in the inner surface ofdoor panel 48 intermediate lower flanges 82, for the reception of acurved rod-like member 58, having oppositely outwardly extending endportions 58 to form pintles adapted to extend outwardly through notches18 formed in flanges 52. The rod-like member 86 is maintained inposition in groove 54 by fuse tube 52, and may be readily assembled inposition merely by withdrawing fuse tube 52 from the apertures inprojections 48 and 88, placing the rod-like member 88 in groove 54 andthen inserting the fuse tube in position, without the necessity of anyother securing means or special tools; The pintle portions 58 on member85 are adapted to pivotally support a supporting link 12 for the fuseand door assembly. As shown in the drawings, supporting link I2comprises spaced side walls 14 apertured adjacent the upper ends thereoffor the reception of pintle por- Integral upstanding tions 58,respectively, and an integral connecting wall 18 also located adjacentthe upper ends of side walls 14 for rigidly connecting the sides ofsupporting link 12. Connecting wall I5 has the upper end thereofprovided with an arcuate cutout portion to permit counter clockwisemovement of the supporting link about pintles 58 by receiving fuse tube52 during such movement.

The lower portion of supporting link 12 is provided with a slot 18opening to one edge of the link and having a reentrant portion at theinner end thereof for receiving pivot pins 82 supported on side walls 8of insulating casing '2. By the provision of such a slot in thesupporting link, it will be apparent that the link may be readilyattached and detached with reing pins 82 into slot 18. In the positionof the 5 parts shown in Fig. 1 of the drawings, it will be noted thatslot 18 in the supporting link lines up with notches 84 provided inopposite side edges of door panel 48 to perminthe link, when assembledwith the fuse and door, to be engaged or disengaged with pivot pins 82.Notches 84 in door panel 48 preferably are flared outwardly tofacilitate easy entrance of pivotpins 82 into the notches and slots 18in the supporting link.

A contact lever 88 of any desired conducting material, such for example,as copper or the like.

is preferably formed with side plate portions 88 vconnected adjacenttheir upper ends, as viewed tion 90 is preferably extended beyond sideplates 88 and bent substantially at right angles to 'form a contactterminal portion 92 for engagement with contact strip 28 of lowercontact assemblyv 20, when the fuse is in operative position. Pref-.

erably, the contact terminal portion 92 also has a an arcuate cutoutportion in the outer end thereof similar to thatin the outer ends ofcontact strip 28 and resilient backing strip 28, to receive fuse tube52. The other end of connecting plate 90 of contact lever 88 is extendedbeyond the other ends of side plates 88 and bent angularly, for example,approximately at an angle of 45 to form a terminal portion 94 to whichthe fuse link tail may be secured. Contact lever 88, is pivotallyassociated with supporting lever I2, by pivot means 98 extending throughcorresponding sides of the supporting link and contact lever and maycomprise rivets or the like. Preferably, the sides 88 of contact lever88 are spaced apart a distance less than the sides I4 of supporting link12, so that the sides 88 of the contact lever will fit between sides I4of the supporting link.

Referring particularly to Figs. 7 and 8 of the drawings, it can be seenthat the terminal portion 94 of contact lever 88 is apertured adjacentthe outer end thereof for the reception of a headed stud 98 havingan-inner portion I00 projecting through terminal portion 94 of thecontact lever, with the inner portion I 00 beingnon-circular in form.The stud 98 also includes an outer threaded portion I02 for cooperationwith a cupshaped nut I 04, the base portion I08 of which is providedwith a threaded aperture for cooperation with the outer threaded portionI02 of the stud. Preferably stud 98 is made from square rod stock'whichis turned to cut threads I02 .and to'cut off the corners of portion I00in a single operation. A washer member I08 is interposed betweenterminal portion '94 of the contact lever and nut I04, and is preferablyrotatably secured to nut I04 by integral tab portions IIO on the washerbeing bent over the open end of nut I04 and into peripheral groove 2 onthe outer surface of the nut in a loose manner to prevent relativeseparating movement of the washer and nut while permitting relativerotative movement thereof. -Washer I08 is provided with an aperture alsonon-circular in form, similar to the form of inner portion I00 of stud98,-so that upon rotation of nut I04, washer I08 is moved longitudinallyof stud 98 but is maintained against rotation on the stud. I

to stress the fuse link in a manner to appreciably alter the ratingthereof; Even where fuse links are provided with strain relief wires,as.

in the fuse link of the'aforementioned patent of James M. Wallace, theseare necessarily limited in strength not only because of spacelimitations, but because it is essential that they be'fused instantlyupon fusion of the fusible portion of the link and consequently cannotwithstand much tension. Fuse links at present are designed to withstanda pull of about ten pounds, and this may readily be exceeded by thecapstan'action and resulting relatively great mechanical ad- .vantageobtained, for example, by securing the tail of the fuse link with theaid of a pair of pliers beneath a rotatable clamping means, such as anordinary bolt and nut. However, with the clamping means of thisinvention, it is obvious that washer I08 which directly engages the fuselink tail to clamp it to terminal portion 94 of contact lever 88, cannotrotate and, therefore,

, can assert no rotative effort on the portion of As stated before, thepurpose of nut I04 is to secure tail 5I of the fuse link to contactlever 88, and the purpose of the specific structure of nut I04, stud 98and washer I08, is toprevent capstan action on the fuse link tail upontightening of nut I04. In other words, it has been the practice in thepast to secure a fuse linktail to a lower fuse terminal by some sort ofrotatable clamping means, so that when the fuse link tail is wrappedabout the clamping means in the direction of rotation thereof to clampthe tail in position, tightening of the clamping means results in acertain amount of rotation of the fust link, tail with the clampingmeans and causes undue tension being placed upon the fusible portion ofthe fuse link, which even though it may not be sufllcient to break therelatively fragile fusible portion of the link, often is enough the fuselink tail in engagement therewith. This is an important feature becauseconsiderable difficulty has been experienced because of damage to fuselinks caused by too much tension being exerted thereon.

With the tails SI of the fuse link secured to terminal portion 94 ofcontact lever 88, it is believed apparent that the contact lever will beprevented from rotating counter-clockwise about its pivot 96. The sidesis of contact lever as are provided with integral forwardly extendinglocking projections II4 adapted to engage be- -neath integral stop lugsII8 provided on door panel 40 when the contact lever is maintained inthe position shown in Fig. 1 of the drawings by fuse link tail 8|, sothat supporting link I2 is positively locked by engagement of projectionH4 and stop lug II8 against rotative movement in' a counter-clockwisedirection about its pivot 88 on the door and fuse assembly or aboutpivot pin 82 on casing 2. Consequently, it can be seen that when a fuselink is inserted in fuse tube 82 and secured at one end by terminal cap88 and at the other end to contact lever 88 by nut I04, the contactlever and supporting link strain on the fuse link, and when the door andfuse assembly are associated with the casing by slipping the notches inthe lower end of the door over pivot pins 82, the door may then berotated in a clockwise direction about pivot pins 82 to bring fuseterminal cap 58 into engagement with upper contact assembly I8, andcontact portion 92 of contact lever 88 into engagement with lowercontact assembly 20 with a. wiping action until latch portion 24 of aresilient backing strip 22 engages over the outer side of terminal cap58 to maintain the door closed and the fuse in closed circuit positionwith respect to terminal assemblies I8 and 20. As the door and fuse aremoved to the closed position shown in Fig. 1,v the fuse terminal cap 58and terminal portion 92 of contact lever 88 eng ge the contact strips ofthe respective terminal assemblies which, as shown, have upwardlydeflected outer ends so that the fuseterminals may be operative to inovethe contact strips upwardly against-the"' bias exertfi" by backingstrips 22 and 28, respectively, to thereby provide both a wipingengagement and final I contact of the contact strips and fuse terminalsobserved that both terminal assemblies I8 and 28, by virtue of the biasexerted'by their backing'strips 22 and 28, respectively, will exert aforce substantially longitudinally of fuse tube projectionfli In theposition of the parts shown in Fig. 2 of the drawings, it will be notedthat substantially all of the door and fuse parts are positionedoutwardly of a vertical plane extending through pivot pins 82 and thatan integral stop projection II6 on each'side plate 88 of the 52, withthe upper contact assembly exerting this force along the axis of fusetube 52, which it will. be noted is displaced outwardly of pivot pins 82so as to tend to cause movement of supporting link 12 in acounter-clockwise direction about pivot pins 82 and therefore tend tobreak the toggle comprising fuse tube 52 and supporting link I2outwardly, and cause movement of the lower end of the fuse tube and dooroutwardly and downwardly to release the upper end of the fuse from latch24. Similarly, lower contact assembly 28 exerts a force on supportinglink 72 at its pivot 96 therewith, which is also offset outwardlyrelative to link pivot supporting pins 82 to also tend to cause movementof the supporting link in a counter-clockwise direction about pivot pins82 and cause movement of the door and fuse outwardly of casing 2.Therefore, when the fuse link blows and fuse link tail 5] is no longeroperative to mainto pivot with supporting link I2 in a counterclockwisedirection out of casing 2 to depend therefrom in the manner shown inFig. 4.

It should be-especially noted that initial movement of fuse58 when thefuse blows, is produced by pressure exerted by both backing strips 22and 28 of" contact assemblies I8 and 28, respectively.

After fuse terminal cap 56 disengages upper contact assembly I8,pressure will continue to be exerted on. contact lever 86 by contactassembly 28 until the parts reach the position shown in Fig. 2, becausethe lever arm from pivot pins 82 to supporting lever pivot 68 beinglonger than the lever arm from pivot pins 82 to contact lever pivot 96,will cause greater movement downwardly of the fuse and its terminal cap56 than of contact lever 86. This action may be further enhanced bycausing backing strip 28 of contact asser'nbly 28 to be stressed agreater amount than 'the backing strip of contact assembly I8 so thatcontact lever has engagement with connecting wall I6 of supporting linkI2, so that continued movement of the door and fuse assembly withsupporting link I2 in a counter-clockwise direction about pivot pins 82under the push given these parts by the force exerted by contactassemblies I8 and 28, will forcibly move contact portion 82 of contactlever 86 from engagement with contact assembly 28. This will not take agreat deal of force because in this position of the parts, contactassembly 28 has substantially assumed its normal position so that littleforce is exerted thereby against contact lever 86. When the fuse blows,of course, contact lever 86 is no longer maintained in the positionshown in Fi 1, so that the contact lever may pivot with supporting linkI2 about its pivot pin 88 an amount sufilcient to clear locking lug H8,and thereafter contact lever 86 will move relative to supporting link I2about its pivot 86 therewith, because of the frictional engagement ofits contact portion 92 with contact assembly 28. This relative movementof contact lever 86 and supporting lever I2 continues, of course, untilthe parts-reach the position shown in Fig. '2 of the drawings, when themomentum of the door and I fuse assembly and parts moving therewithcause disengagement of the contact lever 86 from contact assembly 28. Atthe position of the parts shown in Fig. 2, contact assembly 28 no longerexerts any force on contact lever 86, so that there is no frictionalresistance to continued movement of the fuse and door.

It will be noted that when the fuse and door have moved to an openposition with respect to casing 2 and with respect to the circuitbetween contact assemblies I8 and 28, the door and fuse assembly willassume a depending position as shown in Fig. 4 of the drawings. In thisposition, an aperture I28 in the connecting portion 98 of contact lever86 is exposed, and this aperture has a rounded lower portion, as viewedin Fig. 4, and a narrowed upper portion I22 to present a substantiallypear-shaped opening for the reception of a hook stick operating memberor the like, which may be inserted in opening I28 to lift the door andfuse assembly upwardly and outwardly to remove notches I8 in thesupporting link from pivot pins 82 and detach the door and fuse assemblyfrom the casing without the necessity of manually grasping any of theparts. The particular shape of aperture I28 in contact lever 86 is ofadvantage in that it permits the insertion of the enlarged end of a hookstick so 7 that when the door and fuse assemblies are lifted surface 63on the door to cause movement of the door anrl fuse with the supportinglink after pre- I determined relative movement of the door and link hascaused sumcient downward movement ,and fastened in place by terminal cap56 andv nut I84, after which the fuse and. door may be again assembledwith the casing by lifting it by means of a hook stick inserted inaperture 128 in contactlever 86, to cause slots I. in the supportinglink to telescope over pivot pins 82, whereupon by insertion of a hookstick in aperture 44 in projection 42 on the outer side of door 38, thedoor and fuse assembly may be pivotally moved in a clockwise directionabout the pivot pins 82 into closed position with respect to casing 2,and with respect to the circuit connected to contact assemblies I8 and20. In the attachment and detachment of the fuse and door assembly withrespect to casing 2, the locking of supporting link 12 and contact lever86 to the door 38 by virtueof the inter-engagement of locking projectionIll and locking lug H8 is of particular value in that it prevents unduestress being placed on the fuse link by such attaching or detachingoperations and provides a rigid structure by which the assembly may behandled. I

In the embodiment of the invention shown in Fig. 3 of the drawings, itwill be noted that relative movement of supporting link I2 and the fusetube and door is prevented by a relatively rigid strap member I26secured in position between the fuse tube and door in a manner likerodlike pintle supporting member 86, in that strap I 28 has anintermediate curved portion seated in a slot I24 provided at the innersurface of door .enabling assembly or disassembly of the parts panel 40intermediate flanges '62 for receiving this portion or strap I26 betweenthe door panel and fuse tube 52. The outer ends of strap I26 are bentinwardly towards each other to overlie a downwardly projecting extensionI28 on connecting portion 16 of supporting link I2, to positively securethe link with respect to the door and fuse tube. The projection I28 ofthe supporting link is provided with an outwardly curved central portionI30 extending through connecting portion I6 as shown in Fig. 6 of thedrawings, to enable the link to lie close to fuse tube 52.

Thestrap' I26 for fixedly connecting supporting link I2 to the fuse tubeand door assembly ,may be readily applied to a fuse constructed inaccordance with this invention merely by removing the fuse tube 52 fromthe apertures of supporting projections 48 and 50 on the door, insertingstrap I26 in slotJ2l, and then replacing the fuse tube. In the operationof this embodiment of the invention, when the fuse blows, the biasexerted by contact assemblies l8 and 20 will obviously be inoperative tocause any movement of supporting link 12, and consequently, the fusetube and door will remain latched in the position shown in ig. 1 andwill' not drop out of the circuit.

By the particular method of assembly of the lower contact and supportingmeans for the fuse tube and door assembly to these parts, it is alsopossible to readily assemble in the same manner a means, such as strap I28, for converting the drop-out fuse structure shown in Figs. 1, 2 and 4through 8 of the drawings, to a non-dropout form of fuse cutout in themanner shown in Fig. 3.

From the foregoing, it is believed to be readily apparent that the fusecutout structure herein disclosed is especially adapted to provide forthe fuse and door-assembly to drop out of the circuit when the fuseblows, and that this dropout action is' provided by a novel lower fuseter-' minal and support assembl under the bias exerted by line contacts.Furthermore, the dropout action of the fuse of this invention acts topull out thelower fuse link terminal and iso-.

late the fuse and door assembly from both line contacts so that theassembly will 'be entirely electrically isolated. Ther has also beenherein 75 without the use of any tools whatsoever and in' an extremelyeasy and eiiicient manner. Furthermore, there has also been disclosed inconto the fuse holder terminals with which it is assembled. The latterfeature is especially important in fuses of the dropout type because themeans exerting a biasing action on the fuse to cause it to drop out ofthe circuit when the fuse blows is usually opposed by the fuse linkitself, thereby placing a certain amount of tension on the fuse link, sothat any additional tension placed thereon in assembling it in a fuseholder may readily cause impairment of the link so that it will notoperate properly.

Having described preferred embodiments of the invention in accordancewith the patent statutes, it is desired that the invention beinterpreted as broadly as possible, and that it be not limited to theparticular embodiments disclosed inasmuch as it will be obvious,particularly to persons skilled in the art, that many modifications andchanges may be made in these particular embodiments without departingfrom'the broad spirit and scope of the invention. Accordingly, it isdesired that the invention be interpreted as broadly as possible andthat it be limited only by what is expressly set forth in the followingclaims and by the prior art.

I claim as my invention:

1. In a fuse, spaced line contacts, a fuse holder, a fuse link in saidholder, a support, means mounting said holder on said support formovement into and out of engagement with at least one of said contacts,latch means for maintaining said holder in closed circuit position withrespect to said contacts, said mounting means ineluding a supportinglink pivoted to said holder and to said support, means secured to saidfuse link and engageable with said supporting link and a part movablewith said holder for locking said supporting link against movement withre= spect to said holder, whereby to release said supporting link formovement relative to said holder and permit movement of said holder outof en- Basement with said latch means and with at least said one contactwhen said fuse link blows 2. In a fuse, spaced line contacts, a fuseholdment relative to said holder and permit movement of said holder outof engagement with said latch means and with at least said one contactwhen said fuse link blows.

' 3. In a fuse, vertically spaced line contacts, a fuse tube having aterminal adjacent the upper end thereof, a fuse link in said tube havingone end thereof connected to said terminal, a combined tube terminal andsupporting assembly for the lower end of said tube adapted to supportsaid tube for movement of the terminals thereof into and out ofengagement with said contacts, latch means for maintaining said tubeterminals in engagement with said contacts, said assembly including apivoted supporting link for the lower end of said tube, and a terminalpivoted on said supporting link, the other end of said fuse link beingdirectly connected to said pivoted terminal for maintaining said pivotedterminal in a position to engage one of said contacts and to maintainsaid supporting link in a predetermined supporting position relative tosaid tube, whereby to release said supporting link for movement relativeto said tube when said fuse blows to release said tube from said latchmeans and permit movement of the tube and terminals out of engagementwith said contacts.

4. In a fuse, vertically spaced resilient line contacts, a fuse tubehaving a terminal adjacent the upper end thereof, a fuse link in saidtube having one end thereof connected to said terminal, a combined tubeterminal and supporting assembly for the lower end of said tube adaptedto support said tube for movement of the terminals thereof into and outof engagement with said contacts, latch means for maintaining said tubeterminals in engagement with said contacts, said assembly including apivoted supporting link for the lower end of said tube, aterminalpivotedon said supporting link,the' other end of said fuse link beingdirectly connected to said pivoted terminal for maintaining said pivotedterminal in a position to engage one of said contacts and to maintainsaid supporting link in a predetermined supporting position relative tosaid tube, said tube and supporting link constituting a togglemaintained by said fuse link adjacent its dead-center position, both ofsaid tube terminals adapted to slidably engage lower surfaces of saidcontacts at least .when moved into engagement to obtain pressure wipingcontact and to exert a force substantially longitudinally of said tubein a direction to break said toggle,

including a link pivotally connected to a supporting base and 'saidassembly at spaced points, terminal means pivotally mounted on saidlink, a fuse link mounted in said tube and directly engaging saidterminal means to normally maintain said terminal means and link in apredetermined position relative to said assembly so that said terminalmeans is adapted to engage said contact, and latch means engageable withsaid assembly to maintain said terminal means and contact in engagement,whereby when said fuse blows said link is released for movement relativeto said tube to disengage said latch means and move said terminal meansout bf engagement with said contact.

6. In a fuse, a resilient line contact a fuse tube assembly, meanssupporting said tube assembly for movement toward and away from saidcontact including a link pivotally connected to a supporting base andsaid assembly at spaced points, terminal means pivotally mounted onlinkage, means under the control of said fuse ,link for locking saidsupporting linkage against said link, a fuse link mounted in said tubeand directly engaging said terminal means to normally maintain saidterminal meansand link in a predetermined position relative to said"assembly so that said terminal means is adapted to movement towardand-away from said contact in-' cluding a link pivotally connected to asupporting base and said assembly at spaced points, terminal meanspivotally mounted on said link, a fuse link' mounted-in said tube anddirectly engaging said terminal means to normally maintain said terminalmeans and link in a predetermined position relative to said assembly sothat said terminal means is adapted to engage and stress said contact,and latch means engageable with said assembly to maintain said terminalmeans and contact 'in engagement, whereby when said fuse blows said linkis released for movement relative to said tube todisengage said latchmeans while said terminal means and contact remain in engagement, and tothereafter move said terminal means away from said contact, and saidterminal means pivot being spaced from said spaced points so that saidstressed contact is effective to cause said movements when said .fuse

blows.

8. In a fuse, .a resilient contact, a fuse tube assembly, meanssupporting said tube for movement toward and away from said contactincluding a link pivotally connected to a supporting base and saidassembly at spaced points, terminal means pivotally mounted on saidlink, a fuse link r mounted in said tube and directly engaging said.terminal means to normally maintain said terminal means and link in apredetermined position relative to said assembly s'o that-said terminalmeans is adapted to engage and stress said contact, means on saidassembly engageable by a portion of said terminal means for-positivelypreventing movement of said link and terminal means when in saidpredetermined position, and latch means engageable with said assembly tomaintain said terminal means and contact in engagement, whereby whensaid fuse blows said assembly, terminal means and linkare freed forrelative movement to disengage said assembly from said latch means.

9. In a fuse, spaced line contacts, a fuseholder, a fuse link in saidholder, means mounting said holder for movement into and out ofengagement with at least one of said contacts, latch means formaintaining said holder in closed circuit position with respect to saidcontacts, said mountingmeans including a pivoted supporting movementwith respect to said holder, whereby to release said supporting linkagefor movement relative to said holder and permit movement of said fuselinks blow, and said linkage including an apertured part positioned to.be exposed upon assembly,

movement of said holder out of engagement for the reception of a hookstick or the like.

10. In a fuse, spaced line contacts, a fuse holder, a fuse link in saidholder, means mounting said holder for movement into and out ofengagement with at least one of said contacts, latch means formaintaining said holder in closed circuit position with respect to saidcontacts, said mounting means including a pivoted supporting link,pivoted latch means under the control of said fuse link for locking saidsupporting link against movement with respect to said holder, whereby torelease said supporting link for movement out of engagement with saidlatch means and with at least said one contact when said fuse linkblows, said pivoted latch means including an apertured part for thereception of a hook stick or the like.

11. In a fuse, a resilient line contact, a fuse tube assembly, meanssupporting said tube for movement. toward and away from said contactincluding a link pivotally connected to a supporting base and saidassembly at spaced points, ter-' minal means pivotally mounted on saidlink, a fuse link mounted in said tube and directly engaging saidterminal means to normally maintain said terminal means and supportinglink in a predetermined position relative to said assembly so that saidterminal means is adapted to 1 engage and stress said contact, latchmeans engageable with said assembly to maintain said terminal means andcontact in engagement, whereby when said fuse blows said link isreleased formovement relative to said tube to disengage said latch meanswhile said terminal means and contact remain in engagement, and tothereafter move said terminal means away from said contact, and meanslimiting relative movement of said assembly, supporting link andterminal means to an amount sufficient to release said assembly fromsaid latch means, whereby after such relative movement said assembly andterminal means are adapted to move pivotally with said supporting linkaway from said contact. 12. In an enclosed fuse cutout construction, ahousing having spaced contacts therein, a door and fuse assembly forsaid housing, cooperating pivot means in said housing and on saidassembly for mounting said assembly for movement to and from a positionin which said door closes said housing and said fuse is in bridgingrelation with said contacts, said pivot means constructed to be freelyseparable only in an open position of said means on the outer side ofsaid door providing an aperture for the reception of a hook stick or thelike, the portion of said cooperating pivot means on said assemblymounted on a lever pivoted with said assembly, terminal means pivotallymounted on said lever for engaging one of said contacts, and saidterminal means located at the inner side of said door and apertured forthe reception of a hook stick or the like to remove said assembly fromsaid housing in an open position thereof.

13. In an enclosed fuse cutout construction, a housing having spacedcontacts therein, a door and fuse assembly for said housing, cooperatingpivot means in said housing and on said assembly for mounting saidassembly for movement to and from a position in which saiddoor closessaid housing and said fuse is in bridging relation with said contacts,said pivot means constructed to. be freely separable only in anopenposition of said-assembly, means on the outer side of said doorproviding an aperture for the reception of a hook stick or the like, andmeans forming a part of said assembly at the inner side of said doorprovided with an aperture also fo the reception of a hook stick or thelike to facilitate detachment of said assembly from said housing in anopen position thereof.

14. In a fuse, vertically spaced line contacts, a fuse tube having aterminal adjacent the upper end thereof, a fuse link in said tube havingone end thereof connected to said terminal, a combined tube terminal andsupporting assembly for the lower end of said tube adapted to supportsaid tube for movement of the terminals thereof into and out ofengagement with said contacts, latch means for maintaining said tubeterminals in engagement with said contacts, the other end of said fuselink connected to said terminal assembly, said assembly including apivoted supporting link for said tube, and means preventing relativemovement of said link when said fuse blows to maintain said tubeterminals latched in engagement with said contacts.

15. In a door and fuse assembly for an enlclosed fuse cutout, a housingdoor member having spaced laterally extending apertured supportingportions for receiving'a fuse tube member, supporting means for saidassembly having a part extending between said door and tube members,said part seated in a groove in at least one of said members, said partretained in said groove by the other of said members, and saidsupporting means being otherwise unsecured to said members whereby saidsupporting means is freely removable upon removal of said fuse tubemember from said door member.

16. In a door and fuse assembly for an enclosed fuse cutout, a housingdoor member, a fuse tube member, means detachably securing said memberstogether, supporting means for said assembly having a part extendingbetween said door and tube members, said part seated in a groove in atleastone of said members, said part retained in said groove by the otherof said members, and said supporting means being otherwise unsecured tosaid members whereby said supporting means is freely removable uponremoval of said fuse tube member from said door member.

17. In a door and fuse assembly for an enclosed fuse cutout, a housingdoor member, a fuse tube member, means detachably securing said memberstogether, supporting means for said assembly having a part extendingbetween said door and tube members, said part seated in a groove in atleast one of said members, said part and groove being configurated so asto prevent relative endwise movement thereof, said part retained in saidgroove by the other of said members, and said supporting means beingotherwise unsecured to said members whereby said supporting means isfreely removable upon removal of said fuse tube member from said doormember.

18. In an enclosed fuse cutout door and fuse assembly, a housing doormember, a fuse tube member, means detachably-securing said memberstogether, terminal means for said assembly secured thereto by a partextending between said door and tube members, said part seated in agroove in at least one of said members, said part retained in saidgroove by the other of said members, and said supporting means beingotherwise unsecured to said members whereby said supporting means isfreely refrom said door membe said door and tube members and seated in agroove in at least one of said members, said-part and supporting meanspivotally associated, and means having a portion adapted to-bepositioned between said members and seated in a groove in one of saidmembers for engaging said supporting means to prevent pivotal movementtherof.

20. In a fuse, vertically spaced resilient line contacts, a fuse tubehaving a terminal adjacent the upper end thereof, a fuse link in saidtube having one end thereof connected to said terminal, a combined tubeterminal and supporting assembly for the lower end of said tube adaptedto support said tube for movement of the terminals thereof into and outof engagement with said contacts, latch meains for maintaining said tubeterminals in engagement with said contacts, said assembly including apivoted supporting link for the lower end of said tube, and a terminalpivoted on-said supporting link, [the other end of said fuse link nalsadapted to slidably engage lower surfaces of said contacts at least whenmoved into engagement to obtain pressure wiping contact and to exert aforce substantially longitudinally of said tube, and in a direction tobreak said tog gle, whereby'to release said supporting link for movementrelative to said tube when said fuse blows to release said tube fromsaid latch means and permit movement of the tube and terminals out ofengagement with said contacts and said pivoted terminal adapted tostress its respective contact when moved into engagement therewith anamount such that said contact for said pivoted terminal is efiectiveupon blowing of the fuse, to exert force on said terminal in a directionto cause movement of said tube away from, said contacts even afterdisengagement of said tube and latch means.

21. In a dropout fuse, spaced resilient line contacts, a fuse .tubehaving a terminal, supporting linkage for said tube including a pivotedsupporting lever, a terminal lever pivoted on said supporting lever, afuse link connecting said terminal and terminal lever for maintainingsaid levers in one position wherein said terpivoted supporting link andan auxiliary link pivoted on said main link, and said auxiliary linkdirectly connected to said fuse link, whereby to release said linkagefor relative movement and permit movement of said holder out ofengagement with said latch means and with at least said one contact whensaid fuse link blows.

23. In a dropout fuse, spaced resilient line contacts, a supportinglever, a pair of members each having a terminal portion, each of saidmembers pivoted on said lever at spaced points for movement relative tosaid lever and relative to each other and adapted to engage and biassaid contacts in a manner such that each of said contacts exerts a forceon its respective terminal in a direction to cause movement of saidlever in one direction to move said terminals out of engagement withsaid contacts, and means including fusible means connecting saidtenninals to normally prevent movement of said lever in said onedirection.

positionrelative to said assembly so thatsaid terminal 'means is adaptedto engage said contact, means on said assembly engageable by a portionof said terminal means for positively preventing movement of said linkand terminal means when in said predetermined position, and

latch means engageable with said assembly to maintain said terminalmeans and contact in engagement, whereby when said fuse blows saidassembly, terminal means and link are freed for relative-movement todisengage said assembly from said latch means.

25. In a fuse, spaced line contacts, a fuse holder, a fuse link in saidholder, means mounting said holder for movement into and out ofengagement with at least one of said contacts, latch means formaintaining said holder in closed circuit position with respect to saidcontacts, said mounting means including a supporting link pivoted onsaid holder and on a support, cooperating latch means on said link and apart fixed with respect to said holder, one part of said latch meansbeing movably mounted and secured to said fuse link for lockminal andterminal lever are engaged with said contacts, respectively, and.wherein said levers form with said fuse tube toggle means adjacentvdead-center position, with the force exerted by said resilient contactsacting in a direction to break said toggle means and .cause movement ofsaid fuse terminals away from said contacts.

22. In a fuse, spaced line contacts, a fuse holder, a fuse link in saidholder, means mounting said holder for movement into and out ofengagement with at last one of said contacts, latch means formaintaining said holder in closed circuit position with respect to saidcontacts said mounting means including a main ing said supporting linkagainst movement with respect to said holder, whereby to release saidsupporting link for movement relative to said holder and permit movementof said holder out of engagement with said latch means and with at leastsaid one contact when said fuse link blows.

26. In a fuse, spaced line contacts, a fuse holder, a fuse link in saidholder, means mounting said holder for movement into and out ofengagement with at least one of said contacts, latch means formaintaining said holder in closed circuit position with respect to saidcontacts, said mounting means including a pivoted supporting linkage,means under the control of said fuse link for maintaining saidsupporting linkage against movement with respect to said holder, wherebyto release said supporting linkage for movement relative to said holderand permit movement of said holder out of engagement with said latchmeans and with at least said one contact when said fuse links blow, andsaid linkage including an apertured part positioned to be exposeduponsaid movement-of said holder out of engagement for the-receptionofsaid housing and said fuse is in bridging relation with said contacts,said pivot means constructed to be freely separable only,in an openposition of said assembly, and means mounted on said door at the innerside thereofprovided with; an aperture for the reception of a hookstickor the like to facilitate detachment of said assembly from said housingin an open position thereof with said aperture located in a planesubstantially parallel to the plane of said door.

28. In an enclosed fuse cutout door and fuse assembly, a housing doormember, a fuse tube 31. In a dropout fuse, spaced resilient linecontacts, a fuse tube having a terminal, supporting means for said tubeincluding a supporting lever pivoted to said tube and. to a support, aterminal lever pivoted. on said supporting means adjacent dead-centerposition, with the member, means detachably securing said memberstogether, supporting means for said assembly including a supporting linkpivoted. on said assembly, means connecting said link and assembly forpreventing relative movement thereof, said connecting means maintainedin operative position by .a 'part thereof extending, between saidmembers with said part maintained in a groove formed in one of saidmembers by the other of said members.

29. In a drop-out fuse,, spaced resilient line contacts, a fuse tubehaving. a terminal, supportsupporting link, a terminal lever pivoted onsaid link, a fuselink connecting said terminal and terminal lever formaintaining said linkage in one position wherein said terminal andterminal lever are engaged with said contacts, respectively, and whereinsaid link and fuse"- tube-form toggle means positioned adjacentdead-center at said one position of said linkage, and the force exertedby said resilient contacts acting in a direction to break said togglemeans and cause movement of said fuse terminals away from said contacts.

30. In a drop-out fuse, spaced resilient line contacts, a pivotedsupporting lever, separate cause movement of said lever inone directionto move said terminals out of engagement with said contacts, and meansincluding fusible means connecting said terminals to normally preventmovement of said lever in said one direction.

lever, a fuse link connecting said terminal and terminal lever formaintaining-saidlevers in one position wherein said terminal andterminal lever are engaged with said contacts, respectively, said 10supporting lever and tube forming toggle means between said support andone line contact, said two levers forming toggle means between saidsupport and the other of said contacts, said fuse link normallymaintaining both of said toggle force exerted by said resilient contactsacting f in a direction to break said toggle means'and cause movement ofsaid fuse terminals away fromv said contacts.

tube assembly, means supporting said tube assembly for movement towardand away from said contact including a link pivotally connected to asupporting and said assembly at spaced points, terminal means mounted onsaid link for limited pivotalmoveme'nt relative to said link, a fuselink mounted in said tube and directly engaging said terminal means tonormally maintainlsaid terminal means and link in a predeterminedposition relative to said assembly so that said terminal means isadapted to engage and stress said'contact, and latch means engageablewith said assembly to maintain said terminal means and contact inengagement,

whereby when said fu'se blows said linkis reing linkage for said tubeincluding a pivoted leased for movementrelative to s'aid'tube to dis:

engage 'said latch means while said terminalmeans and contact remain inengagement by virtue of relative movement of said terminal ing saidholder for movement into and out of fuse link for locking saidsupporting linkage .tive movement said terminal means is moved away fromsaid contact. v

33. In alfu'se, spaced line contacts, a fuse holder, a fuse-link in saidholder, means mountengagement with at least one of said contacts, latchmeans for maintaining said holder in closed circuit position withrespect to said contacts, said mounting means" including a pivotedsupporting linkage, means under-the control of said against movementwith respect to said holder, whereby to release said supporting linkagefor movement relative to said holder and permit movement of said holderout of engagement contact when said fuse links -.with said latchmeans-and withat least said one blow.

32. In a fuse, a resilient line contact, a fuse HERBERT IL. mwims'. v

